"The ICR agreements with Vodafone, Aircel and Reliance Jio are in the final stages and these are likely to be completed by March 31," BSNL Chairman and Managing Director Anupam Shrivastava told PTI.

At this point of time, BSNL is looking into legal and techno-commercial aspects of the agreement.

Other than these three players, he said, testing of network is going on with Airtel and Telenor.

"We are looking at a revenue potential of Rs 500 crore on annual basis through ICR agreements with other operators," Shrivastava said.

As per the ICR agreement, BSNL will charge 25 paise per call for a minute, 3 paise an SMS and 25 paise per MB for data usage. The telecom firm will pay the same charges to other operators for using their network.